1. Field of the Invention
This invention relates to an optical apparatus of the kind arranged to convert the result of a manual operation into an electrical signal or the like and to move an optical member such as a lens by driving a power source such as a motor according to the electrical signal.
2. Description of the Related Art
It is known to arrange a power focusing device or a power zooming device to permit a manual rotating operation on a focus ring or a zoom ring, to convert the result of the manual operation into an electrical signal and to move a focusing lens or a power varying lens by driving a power source according to the electrical signal, as disclosed, for example, in U.S. Pat. No. 4,864,344. Interchangeable lenses which are equipped with the power focusing or zooming devices of this kind for single-lens reflex cameras are now on the market. The lens moving direction in relation to the rotating direction of the focus or zoom rings of these interchangeable lenses, however, varies with the manufacturers of them. While an interchangeable lens made by a manufacturing company A is arranged, for example, to move a lens unit forward when the ring is manually rotated clockwise, an interchangeable lens made by another manufacturing company B is arranged to move the lens unit backward when the ring is manually rotated in the same direction.
Since the moving direction of the lens in relation to the rotating direction of the rotary operation ring of the commercially available interchangeable lenses which are of the kind having a power manipulating type lens-driving device such as a power focusing device or a power zooming device varies with the manufacturers of them, as mentioned above, a camera operator accustomed to using an interchangeable lens made by one manufacturing company A tends to erroneously operate an interchangeable lens made by the other manufacturing company B. The product of the manufacturing company B, therefore, cannot be adequately used even if the operator wishes to use it.